杭州剧院的声学模型试验
THE EXPERIMENTS OF ACOUSTIC MODEL FOR HANGZHOU THEATRE
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摘要: 杭州剧院是一座多功能厅堂,观众厅的体积约10000m3,能容纳2000观众席,已于1978年9月竣工使用,观众反映音质效果比较好。在我们进行音质设计过程中,为了及早对设计方案作出评价,作了1:10的声学模型试验。本文概括给出某些试验的结果,并与剧院建成后实测进行比较。模型试验包括(1)木条子墙和“船形”扩散体天花的声学特性,(2)吸声材料的模拟,(3)混响时间,(4)反射声,(5)声场分布,(6)观众对前次反射声的影响,(7)方向性扩散,(8)清晰度,(9)主观评价。模型和实物的对比结果:满场的混响时间除250Hz的差别较大外(约20%),其余频率比较接近(差别少于10%);反射声图形是相似的;声场分布的差别少于2dB;观众对从台口侧墙来的前次反射声有影响,衰减约6dB;方向性扩散低于实测值,这是由于制造模型时省略一些细部所引起;清晰度和主观评价与观众的实际感受大致相符。Abstract: The Hangzhou Theatre is a multipurpose auditorium having a seating capacity of 2,000 and a volume of about 10,000 m3. Completed in Sept. 1978, it is general agreed that the acoustics of the auditorium is good. In the course of designing the acoustics, we proceeded experiment with acoustical model of scale 1:10 in order to make an initial evaluation for the design.This paper gives comprehensively some experimental results and compares it with the actual measurements in the theatre after completion. The experiments of model consist of (1) the acoustical characteristics of screen slat strueture and the boat-diffuser on the ceiling, (2) the simulation of absorptive materials, (3) the reverberation time, (4) the reflected sound, (5) the distribution of sound field, (6) the effect of early reflective sound for audience, (7) the directional diffusion, (8) the definition, (9) the subjective assessment. The results of model compare with aetual hall:except 250 Hz (difference about 20%), the reverberation time (occupied) at various frequency were close(difference less than 10%); the difference of sound field distribution less than 2 dB; the early-reflected sound from side walls of proscenium over audience attenuated about 6 dB; the value of directional diffusion less than actual measurements, because we neglected the details while making the model; the definition and subjective assessment agreed well.